Preps for v1.6.0 release

Update README, release notes the mynewt repository file, and imgtool for
the v1.6.0 release.

Signed-off-by: David Brown <david.brown@linaro.org>

README.md

@@ -6,7 +6,7 @@
 [coverity]: https://scan.coverity.com/projects/mcuboot
 [travis]: https://travis-ci.org/JuulLabs-OSS/mcuboot
 
-This is mcuboot version 1.6.0-rc2
+This is mcuboot version 1.6.0
 
 MCUboot is a secure bootloader for 32-bit MCUs. The goal of MCUboot is to
 define a common infrastructure for the bootloader, system flash layout on

docs/release-notes.md

@@ -35,8 +35,8 @@ updates as well.
 ### Zephyr-RTOS Compatibility
 
 This release of MCUboot works the Zephyr "master" at the time of the
-release.  It was tested as of has aff616de20.  When Zephyr v2.3.0 is
-release, there will be a possible 1.6.1 or similar release of Zephyr
+release.  It was tested as of has 1a89ca1238.  When Zephyr v2.3.0 is
+released, there will be a possible 1.6.1 or similar release of Zephyr
 if needed to address any issues.  There also may be branch releases of
 MCUboot specifically for the current version of Zephyr, e.g.
 v1.6.0-zephyr-2.2.1.

repository.yml

@@ -29,10 +29,10 @@ repo.versions:
     "1.3.1": "v1.3.1"
     "1.4.0": "v1.4.0"
     "1.5.0": "v1.5.0"
-    "1.6.0": "v1.6.0-rc2"
+    "1.6.0": "v1.6.0"
 
     "0-dev": "0.0.0"        # master
-    "0-latest": "1.5.0"     # latest stable release
-    "1-latest": "1.5.0"     # latest stable release
+    "0-latest": "1.6.0"     # latest stable release
+    "1-latest": "1.6.0"     # latest stable release
 
-    "1.0-latest": "1.5.0"
+    "1.0-latest": "1.6.0"

scripts/imgtool/__init__.py

@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-imgtool_version = "1.6.0rc2"
+imgtool_version = "1.6.0"